• 약학회지
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• 제41권1호
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• pp.30-37
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• 1997

In order to formulate a controlled release system for oral drug delivery, the microcapsules were prepared in w/o emulsion containing cefaclor as a water-soluble model drug by th e method of interfacial polycondensation. Gelatin wis selected as a suitable polymer for interfacial polycondensation. Gelatin solution containing drug was emulsified in an organic phase under mechanical stirring. After emulsification, terephthaloyl chloride was added as cross linking agent, followed by mechanical stirring, washing and drying. Physical characteristics of microcapsules were investigated by optical microscopy, scanning electron microscopy and particle size analysis. Mean particle sizes of gelatin microcapsules were, in the range, of about 20~50 ${\mu}$m. The microcapsules were in good apperance with spherical shapes before washing, but were destroyed partially after washing and drying, even though some microcapsules were still maintained in their shapes. Contents of cefaclor in the microcapsules were calculated by UV spectrophotometry after 3 days extraction with pH 4 carbonate buffer solution. The effects of cross linking time. pH. concentration of cross-linking agent, and temperature on drug release kinetics have been discussed extensively.

• 한국식품저장유통학회지
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• 제9권2호
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• pp.194-199
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• 2002

천연식초를 이용하여 분말식초의 제조방법을 개발하고 아울러 분말식초의 품질특성 및 제조공정을 평가하여 분말식초의 제조 가능성을 검토하고자 하였다. 식초와 포접물질을 혼합한 포접물의 최적 농도는 피복물질의 양이 많을수록 흡습이 잘 되지 않고 열에도 안정함을 보였으나 포접물질의 양이 증가할수록 포접물질의 맛이 강하게 나타나 식초의 고유한 관능적인 특성이 떨어지므로 포접물의 농도를 30。bx 로 결정하였다. 분무건조공정을 최적화하기 위해 인입온도와 flow rate를 독립변수로 하고 분말식초의 품질특성을 나타내는 수분, 산도, 흡습성, 당함량, 열안정성 등을 종속변수로 하여 반응표면분석법을 실시한 결과, 분무공정의 최적조건은 inlet temperature는 19$0^{\circ}C$, flow rate는 550 L/h로 결정할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제19권2호
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• pp.99-107
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• 1989

In order to develop a pediatric liquid preparation with sustained release properties, dextromethorphan hydrobromide (DEXT) was complexed with strong cation exchange resin (CG 120) and the-complex was coated with Eudragit RS using a phase separation method by non-solvent addition. The effect of pH, ionic strength of the release medium and drug/resin ratio on the release rate of DEXT was studied. The release rate of free drug from the uncoated complex, and coated complexes with 9.5 and 18.5% Eudragit RS in artificial gastric juice were measured. The release rate from the uncoated complex was faster with higher pH, higher ionic strength of the release medium and higher drug/resin ratio. The release rate from the coated complex could be controlled by the amount of coating material, and the surface after release did not rupture into.

• 설비공학논문집
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• 제15권5호
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• pp.352-359
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• 2003

The present study has been conducted for manufacturing MPCM (microencapsulated phase change material) slurry with in-situ polymerization and proving their applicabilities for tooling system. The surface of MPCM is composed of melamine, while tetradecane, paraffin wax, is centered in the MPCM. The produced capsules are observed by the optical microscope and SEM for superficial shapes. Their thermal properties are measured by DSC. Their size distributions are observed by FA particle analyzer. A narrow size distribution from 1 to 10 ${\mu}{\textrm}{m}$ with 5 ${\mu}{\textrm}{m}$ of average diameter was observed. Melting temperature was 6.7$^{\circ}C$. The durability of MPCM was tested with various types of pump such as centrifugal, peristaltic, and mono pumps. During 10000 cycles the fraction of broken capsules was smaller than 6% for the centrifugal and peristaltic pumps, while bigger value of 8% for the mono pump. A cooling system, which adopted MPCM slurry as a media for transporting cold thermal energy, was designed to investigate the performance of the MPCM. The discharging times of 10 and 20 wt% MPCM slurry were lasted up to 105 and 285 minutes longer, respectively, than the water cooling system.

• 약학회지
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• 제32권1호
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• pp.26-39
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• 1988

Eudragit $RS^{\circledR}$ polymer was used as a wall material for the microencapsulation of aspirin by a phase separation method from chloroform-cyclohexane system with 5% polyisobutylene (PIB) in cyclohexane, and microcapsules obtained were evaluated by particle size analysis, scanning electron microscopy (SEM), drug release and drug stability test. With PIB as a coacervation inducing agent, smooth and tight microcapsules with less aggregation were obtained. Below 1 : 0.3 core-wall ratio, it was possible to coat individual particle. Variation of production conditions showed that increasing the proportion of wall material, particle size and wall thickness of microcapsules and the concentration of paraffin wax in cyclohexane as a sealant sustained drug release rates effectively. SEM confirmed that larger microcapsules after drug release did not rupture into smaller particles but contained a few small pores on the surface. Aspirin release from Eudragit $RS^{\circledR}$ coated microcapsules was independent of the pH of medium, and the mechanism of drug release from non-sealed and sealed microcapsules appeared to fit Higuchi matrix model kinetics. Aspirin in the mixture of aspirin microcapsules and sodium bicarbonate was by far more stable than that in the mixture of pure aspirin and sodium bicarbonate.

• Archives of Pharmacal Research
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• 제26권10호
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• pp.874-879
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• 2003

The present study was carried out to examine the stability of microencapsulated ascorbic acid in simulated-gastric and intestinal situation in vitro and the effect of microencapsulated ascorbic acid on iron bioavailability. Coating materials used were polyglycerol monostearate (PGMS) and medium-chain triacylglycerol (MCT), and core materials were L-ascorbic acid and ferric ammonium sulfate. When ascorbic acid was microencapsulated by MCT, the release of ascorbic acid was 6.3％ at pH 5 and 1.32％ at pH 2 in simulated-gastric fluids during 60 min. When ascorbic acid was microencapsulated by PGMS, the more ascorbic acid was released in the range of 9.5 to 16.0％. Comparatively, ascorbic acid release increased significantly as 94.7％ and 83.8％ coated by MCT and PGMS, respectively, for 60 min incubation in simulated-intestinal fluid. In the subsequent study, we tested whether ascorbic acid enhanced the iron bioavailability or not. In results, serum iron content and transferring saturation increased dramatically when subjects consumed milks containing both encapsulated iron and encapsulated ascorbic acid, compared with those when consumed uncapsulated iron or encapsulated iron without ascorbic acid. Therefore, the present data indicated that microencapsulated ascorbic acid with both PGMS and MCT were effective means for fortifying ascorbic acid into milk and for enhancing the iron bioavailability.

• Journal of Pharmaceutical Investigation
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• 제32권1호
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• pp.41-45
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• 2002

The purpose of this study is to microencapsulate a highly hygroscopic drug, pyridostigmine bromide (PB), with a waterproof wall material, in order to increase the flowability of the drug particles. Polyvinylacetaldiethylaminoacetate (AEA), Eugragit E and Eugragit RS were examined as the wall materials. Microcapsules containing PB were prepared by the evaporation technique in an acetone/liquid paraffin system using aluminum tristearate as a core material, and evaluated for drug encapsulation efficiency, surface morphology, particle size and drug dissolution. The encapsulation of PB in the wall material was almost complete. Among the wall materials examined, AEA exhibited the most excellency in shape, surface texture, flowability, size distribution of microcapsules. Above results suggest that AEA would be a potential wall material for microcapsulation of highly hygroscopic drugs, such as PB. Through microencapsulation with AEA, inconvenience of handling of PB powders encountered in the process of weighing and packing the powders to tableting die or capsule body could be greatly improved.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.113-120
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• 2020

The objective of the study was to assess the survival of microencapsulated Lactobacillus plantarum ATCC8014 produced using the emulsion technique in alginate gel combined with pectin and maltodextrin components. The microcapsules were then added to cupcake dough that was further baked at 200℃ for 12 min. The viability of L. plantarum was assessed during baking and the 10 days of storage at 4℃ as well as in simulated gastrointestinal conditions. In addition, yeast-mold and water activity were investigated. After baking, the samples with microencapsulated L. plantarum contained more than 5 log CFU/g, which was higher compared to the bacterial concentration of the control samples. The concentration of L. plantarum was more than 6 logs CFU/g after the end of the storage; therefore, the probiotic functioned as a biopreservative in the cake. The prebiotic component strengthened the microcapsules network and helped protect the viability of L. plantarum in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) media. The results show that the addition of L. plantarum microencapsules did not affect the sensory scores of the cupcake while ensuring the viability of the probiotic during baking and storing.

• International Journal of Air-Conditioning and Refrigeration
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• 제13권4호
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• pp.175-183
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• 2005

The present study has been conducted for manufacturing MPCM (microencapsulated phase change material) slurry with in-situ polymerization and proving their applicabilities for cooling system. The tetradecane as a core material of MPCM is coated with melamine. The produced capsules are observed by the optical microscope and SEM for superficial shapes and analysed their properties by DSC and particle size distribution by FA particle analyzer. It is found that narrow size distribution in 1 to $10{\mu}m$ is resulted in $5{\mu}m$ of average diameter and $9^{\circ}C$ melting temperature. The durability of MPCM capsules is tested with various types of pumps such as centrifugal, peristaltic, and mono. For the centrifugal and peristaltic pumps the breakage fraction of the capsules is resulted within $6\%$ during 10,000 cycles, while the mono is over $8\%$. The cooling system, which has adopted MPCM slurry as a medium for transporting cold thermal energy, is designed to investigate the performance of newly developed coolant. The discharging times of cold energy in circulating 10 and $20wt\%$ MPCM slurry are lasted to 105 and 285 minutes, respectively.

• 한국미생물·생명공학회지
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• 제49권2호
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• pp.201-209
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• 2021

Agarwood (Aquilaria spp) has high economic value. However, essential oil production from agarwood is a time-consuming process. Additionally, agarwood leaves have not been utilized even though they contain various bioactive ingredients. In this study, agarwood leaves were fermented using Lactobacillus plantarum ATCC 8014 with or without Stevia (4, 8, and 12%; v/v). The fermented fluid was mixed with maltodextrin (15%; w/v) and subjected to spray drying (inlet temperature, 120℃; outlet temperature, 65-70℃). The contents of polyphenols, polysaccharides, saponins, and flavonoids and the viability of L. plantarum were determined. Fermentation enhanced the levels of bioactive compounds. The contents of polyphenol (69.19 ± 4.05 mg GAE/g of sample), polysaccharide (20.75 ± 0.98 mg GE/g of sample), saponin (305.23 ± 4.21 mg OAE/g of sample), and flavonoid (7.86 ± 0.72 mg QE/g of sample), and the viability of L. plantarum (8.72 ± 0.17 log CFU/ml) were markedly upregulated in the samples containing Stevia (12%; v/v). This indicated that the supplementation of Stevia during fermentation decreases the fermentation time (9 h), upregulates bioactive compound production in agarwood leaves, enhances microencapsulation during spray drying, and increases the viability of L. plantarum under simulated gastric digestion conditions.